1. Field of the Invention
The invention relates to devices for treating human hair in order to straighten it or to form it into desired patterns. More particularly, the invention relates to electrical hair treating appliances having electrical resistance heating wires embedded therein for curling or straightening hair.
2. Description of the Prior Art
Hair wrappers are known in the prior art and are generally used as heated hair curling devices. These wrappers usually comprise thin, rectilinear laminated structures having low voltage electrical resistance wires embedded therein and are provided with an attached flap or fold to cover the hair tress. These devices are flexible enough to be rolled and are often used on wet or moistened hair to vaporize the moisture and set the desired curl.
Hair wrappers, sometimes called roll-up type hair curlers, are differentiated from conventional hair rollers. Both may be used to roll hair using the croquinole method (rolling from the tip of the hair tress toward the scalp). However, using a hair wrapper results in maintaining a uniform separation between the heating elements and all parts of the hair tress while using a roller, whether it is heated internally or from an external source such as a hair retaining clip, results in some portions of the hair tress drying before others. Because hair wrappers more uniformly heat hair, a lower temperature may be employed than with a roller to achieve the same result. Also, if the heat can be generated after the wrapper is rolled on a hair tress then a user need not be concerned with the hair drying while it is being rolled, as with conventional heated hair rollers.
An example of a hair wrapper device is shown in U.S. Pat. No. 1,990,547 which discloses a rectilinear laminated structure with an embedded metallic foil arranged in a single serpentine pattern terminating in tab-type electrical terminals which are accessible even after hair is wound on the device. The device is rectangular for being generally aligned with a hair tress and has a rectangular absorbent flap attached to one longitudinal edge of the structure to be folded over the hair tress. The folded wrapper with the hair tress retained therein may then be rolled in the croquignole style. The disadvantage associated with such a device is that requires two electrical connections to be made once the hair has been curled in the wrapper. This requires some care in assuring that the electrical terminals are properly placed.
Another type of prior art device is shown in U.S. Pat. No. 1,883,828. This device also utilizes a rectangular laminate having a single serpentine flat metal or wire pattern embedded therein. However, this device also has two electrical terminals at the ends of the wire and although the terminals may be bent to extend from the end of the roller, some care must be taken to place the terminals conveniently away from the scalp to minimize discomfort.
It is also known to provide a shape-memory curl forming wrapper having a base and two flaps as shown in U.S. Pat. No. 3,109,438. Such device does not however include internal heat generating means.
Another type of electrically heated curling device is shown in U.S. Pat. No. 3,347,248 which discloses a hair curler assembly having electrical resistance wire embedded in either the roller and/or the clip intended to retain the hair on the roller. The device disclosed in this patent also shows simple plug/socket construction to interconnect all of the rollers in series to electrically heat them all simultaneously. This device is, however, a roller rather than a wrapper and cannot, therefore, operate with the same characteristics as the latter.
All of the known prior art hair wrappers utilizing embedded electrical resistance wire elements require that each hair wrapper be made individually with discrete lengths of resistance foil or wire. This limitation adds an unnecessary and, therefore, costly complication to the manufacture of such devices and it is accordingly an object of this invention to provide a hair appliance which overcomes this disadvantage.
Additionally, all of the known prior art hair wrappers which utilize electrical resistance heating require cumbersome connection techniques for connecting the resistance wire terminals to a source of electrical power. Consequently, it is yet another object of this invention to provide a hair curling wrapper which facilitates the connection of the wrapper to a source of electrical power.
It is yet another object of this invention to provide a hair curling wrapper which can be used either for straightening hair or curling it in a variety of patterns.